Adjuvants have the potential to impact or even determine the success or failure of vaccine compositions. Additionally, adjuvants often determine or augment the administration method of a given antigen. Further, in the area of DNA and gene vaccines used for therapeutic or prophylactic purposes it is thought that the use of Ca++ and divalent cations are required for efficacy when making a DNA vaccine. The Ca++ and divalent cations are often added to or formed as a derivative of liposomal delivery vehicles that are unstable when suspended in aqueous (water) solutions. These steps and production of these materials are time consuming and add to the cost of vaccine manufacturing. It is known in the art that DNA vaccines require multiple doses in order to elicit an immune response that protects the recipient against a challenge. Further, DNA vaccines require high doses of DNA ranging from a few hundred micrograms to milligrams of purified DNA per dose.
All routes of vaccine administration could benefit from enhanced efficacy and controlled formulation including the ability to use less antigen to receive the same or better immunogenic response. What is needed in the art are adjuvant compositions that can be formulated to suit DNA vaccines that do not require the use of cations or liposomal delivery vehicles. Further, adjuvant formulations are needed that provide an efficacious vaccine after a single dose of the vaccine. Such compositions place less stress on the recipient and are more cost-effective. Finally, compositions with improved capability such as onset and duration of immunity are also needed in the art. Compositions that can be delivered by multiple routes of inoculation such as intravenous, subcutaneous, intramuscular, transdermal, oral, and mucosal are also needed in the art.